Heat stabilized compositions containing alkoxyphenylglycidyl ethers



United States Patent f" HEAT STABILIZED COMPOSITIONS CONTAINING ALKOXYPHENYLGLYCIDYL ETHERS Alan Bell, Kingsport, Tenn., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application November 2, 1953, 8 Serial No. 389,839

8 Claims. (Cl. 106-176) This invention relates to novel stabilizers for thermoplastic compositions and more particularly to compositions comprising cellulose esters and vinyl polymers stabilized as to flow and color by the incorporation therein of relatively small amounts of the compounds of the invention.

The stabilizing effect of various glycidyl ethers of resorcinol and hydroquinone, e. g. hydroquinone bisglycidyl ether and resorcinol bisglycidyl ether has been known and utilized in the art for some time. The possibility of improved stabilizers which are more compatible with the plastic compositions has been investigated for the purpose of improving the character of these compositions.

I have discovered that a certain class of alkoxyphenyl glycidyl ethers is extremely effective in the heat stabilization of these compounds while offering the additional advantage of being more compatible and soluble in the plastic base, particularly as applied to cellulose ester com positions. I have also found that the position of the alkoxy group on the benzene ring is of unuusal significance in the effectiveness of my new class of stabilizers. Whereas it has been determined that the stabilizing efiect' of glycidyl type compounds may in general be said to be in direct relation to the amount of oxirane oxygen contained in the compound, I have found unexpectedly that the new class of stabilizers is equally as effective as compounds in the prior art containing approximately twice 7 the amount of oxirane oxygen.

It is therefore a principal object of the present invention to provide improved stabilizers for thermoplastic compounds and compositions, e. g. cellulose esters and vinyl 2,805,170 Patented. Sept. 3,

erably employed in an amount within the range of about 0.5% to about 4.0%, most advantageously about 2.0%, of the weight of the plastic compound.

The stabilizers of the invention may be prepared by the reaction of an appropriate alkoxyphenolwith epichlorohydrin in alkaline solution. The reaction may be represented by the following equation:

The invention is illustrated in the following examples:

Example 1.-Preparati0n of I (2,3 epoxypropoxy) 4- methoxybenzene of epichlorohydrin. The mixture was then stirredovernight at room temperature. The white solid which had polymers. It is a further object of the invention to provide novel and improved heat and color stabilized thermoplastic compositions comprising cellulose esters of vinyl polymers. A further object is to provide novel com- I pounds comprising oand p-alkoxyphenylglycidyl ethers. In accordance with my invention cellulose ester and vinyl polymer thermoplastic compositions having im-' I proved heat stability as regards flow, color, and melt and intrinsic viscosity are prepared by incorporating a relatively small stabilizing amount of an alkoxyphenylglycidyl ether selected from the group consisting of oand p-alkoxyphenylglycidyl ethers. Preferably the alkoxy group comprises an unsubstituted acyclic alkyl radical of 1 to 4 carbon atoms inclusive. The stabilized compounds may also contain plasticizers and other stabilizing compounds. The novel stabilizer may be incorporated in the thermoplastic base by intimate dispersion therein in accordance with known procedures.

A most advantageous embodiment of the invention consists in a plastic composition of cellulose a'cetate or cellulose acetate bu'tyrate containing dibutylsebacate as plasticizer and oor p-methoxyphenylglycidyl ether, either alone or in combination with additional stabilizer comprising p-tertiary butyl phenol, potassium acid oxalate also preferably being present as a flow stabilizer. The

oand p-alkoxyphenylglycidyl ether stabilizers are prefcontent was 8.16%.

yield was 400 parts of a product which melted' at 36-38" C. This material contained by analysis-7.2 percent epoxy. The crude product was recrystallized 'from' hexane and melted at 3940 C. The product was then further purified from benzene-hexane to give white crystals, Ml P. 43-435 C. Analysis calcd. for C1oH'1203; (3,166.65; H, 6.71; epfoxy, 8.85. Found: C, 66.63; H, 6.89; epoxy 7.62. The epoxy analysis is usually low in compounds of this type. v

Example 2. -Preparation of I (2,3 epoxypropoxy -4- butoxybenzene This product was prepared in a manner similar to the procedure describedir'i Example 1 except that th'e'rnonobutyl ether of hydroquinone was used. The productwas distilled at 142-50 C. (1 mm.) to give a 60% yield of a white crystalline solid, M. P. 34-35 C. (epoxy 7.41%).

Example 3.Preparati0n 0 I-benzyloxy-4-(2,3-epoxypropoxy) benzene This material was also prepared by the procedure described in Example 1. The product distilled at 18288 (0.5 mm.) and melted at 58-60 C. (epoxy content-was 6.01%; theory 6.2).

Example"4. Prparati0n' of 1 (2,3 epoxypropbxy) --2- 'Erizri tp'le 5. -Preparati0n of 1 (2,3 epoxypr0p0xy) 3- methoxybenzene This product was .prepared ina similarirnanner from resorcinol monomethyl ether and epichlorhydrin.; It was methozybenzene; KHOX is potassium acid oxalate.

Samples of the p-methoxyphenylglycidyl ether (1-[2,3- epoxypropoxy] -4-methoxybenzene) prepared in Example 1 were tested with the results as shown in Table I below. In these tests, a cellulose acetate butyrate composition of about 12-13% acetyl and 36-38% butyryl content, prepared in accordance with the disclosure of U. S. Patent No. 2,048,685 was treated with plasticizen potassium acid oxalate flow stabilizer and various stabilizers. The tests were run by injection molding of the various compositions and subjecting the pellets punched from these specimens to the 205 C. heat test. In each case, 100 parts of ester and 4 parts of plasticizer were used. 4 p p The results of these tests indicate that the l-(2,3 epoxypropoxy)-4-methoxybenzene is as effective in both flow and color stabilizing as resorcinol bisglycidyl ether. The tests made using p-tert-butylphenol in combination with the other stabilizer indicated that the'combinations were essentially equal to each other. These results were unexpected since resorcinol bisglycidyl ether contains 13.3% oxirane oxygen while the 1-(2,3-epoxypropoxy)- 4-methoxybenzene contained only 7.2%. This latter compound is theefore an improvement since it is much formulations than resorcinol bisglycidyl ether or hydroquinone bisglycidyl ether.

It will be readily observed that the introduction of the p-methoxy group into phenylglycidyl ether results in a compound which gives much better heat stabilization. The 1-(2,3-epoxypropoxy)-4-methoxybenzene is also a better heat stabilizer than either resorcinol bisglycidyl ether or hydroquinone bisglycidyl ether, both of which contain more than twice the epoxy content.

Example 8.Heat stabilization of cellulose acetate Another series of tests were carried out using 100 parts of cellulose acetate (-second, 39.4%) 50 parts of tripropionin, and 2 parts of stabilizer. The results listed in Table III are expressed as the percent decrease in intrinsic viscosity after application of heat at 205 C. for one hour.

TABLE I [Screening tests using salt-tree ester] Original l-Hour Heat Test 2-Hour Heat Test Pigfiszsta- Stabilizer a Flow, F. Color Haze Flow, F. Color Flow, "F Color .007 317 70 15 300 55 20s 55 .015 315 70 25 300 45 305 55 .025 315 70 55 312 30 310 05 j .005 320 so 45 311 25 311 45 0. .005 30s 55 12 an 40 310 50 0 .010 314 00 20 s14 25 31a 50 0 .018 315 70 25 317 35 315 45 0 .025 315 so 311 315 55 0. .005 510 70 12 315 25 315 55 0. .010 321 05 20 s14 55 311 15 0. .018 324 55 31s 35 s11 45 0. .020 324 55 s10 35 317 50 3- .005 321 50 1 15 511 35 315 45. g- .010 321 55 25 31s 45 311 05 I g- .01 s s22 70 30 31s 35 31s 45 .g- .020 322 V 70 30 51s 35 31s .50 -g- .005 315 s0 15 314 35 314 15 p g .010 315 s0 20 an: 25 3'11 55 .018 315 a0 so 314 35 311 45 012 MPG :02 .025 31a s5 35 315 45 318 05 RBGE is resorcinol bisglycidyl ether; PTBP Q Example 7.Heat stabilization of cellulose acetate Table II gives results of heat stability tests at 190 ..C. for /5 hour using 1% of various stabilizers in ,a formulation containing 7.5 g. of cellulose acetate (SO-second, 39.4% acetyl) and 10 cc. of tripropionin.

TABLE 11 Percent Loss in Percent Viscosity. Stabilizer Epoxy 7 Melt Intrinsic Non 85 40 Phenylglyeidyi ether 8.2 25 21 Resorcinol bisglycidyl ether 13. 3., w 7 13 Hydroqninone bisglycidyl ether 13. 2 0 19 1-(2,3ep0xyprop0xy)4-methoxybenzene 6. 1 1 0 5 p-tert-butylphenol; MPGE 'is 1-(2,3-epoxypropoxy)-4- It will be observed in this series of tests that there is a distinct difierence in function between the ortho and and the meta alkoxy derivatives.

I claim: w

1. A- composition'of" matter comprising a cellulose ester plastic molding composition selected from the group consisting of cellulose acetate and cellulose acetate bu- 7 tyrate and a small stabilizing amount of an alkoxyphenylglycide ether selected from the group consisting of oand p-alkoxyphenylglycide ethers in which the alkyl radical of the alkoxy group is an unsubstituted acyclic alkyl radical of 1 to 4 carbon atoms inclusive. P 1

V 2. A composition of matter comprising cellulose acetate and a small stabilizing amount of an alkoxyphenylglycide ether selected from the group consisting of oand palkoxyphenylglycide ethers in which the alkyl radical of the alkoxy group is an unsubstituted acyclic alkyl radical of l to 4 carbon atoms inclusive.

3. A composition of matter comprising cellulose acetate butyrate and a small stabilizing amount of an alkoxyphenylglycide ether selected from the group consisting of oand p-alkoxyphenylglycide ethers in which the alkyl radical of the alkoxy group is an unsubstituted acyclic alkyl radical of 1 to 4 carbon atoms inclusive.

4. A composition of matter comprising cellulose acetate butyrate and 1-(2,3-epoxypropoxy)-4-methoxyben- 5. A composition of matter comprising cellulose acetate butyrate and 1-(2,3-epoxypropoxy)-4-butoxybenzene.

6. A composition of matter comprising cellulose acetate butyrate and l-benzyloxy-4-(2,3-epoxypropoxy)benzene.

7. A composition of matter comprising cellulose acetate and as a heat stabilizer therefor 0.2 parts by weight of 1- (2,3-epoxypropoxy)-4-methoxybenzene, as an additional stabilizer approximately 0.2 parts by weight of p-tertiary butylphenol, as a plasticizer approximately 4 parts by weight of dibutyl sebacate and as a flow stabilizer less than .03 parts by weight of potassium acid oxalate.

20 Erganzungswerk, 1934, vol. 17, page 51.

8. A thermoplastic composition selected from the group consisting of cellulose acetate and cellulose acetate butyrate stabilized against color development and degradation of melt-viscosity at molding temperatures by the presence of about 0.5 to about 4.0 parts by weight of the thermoplastic composition of 'an alkoxyphenylglycidyl ether selected from the group consisting of o-and palkoxyphenylglycidyl ethers in which the alkyl radical of the alkoxy group is an unsubstituted acyclic alkyl radical of 1 to 4 carbon atoms inclusive said ether being intimately dispersed in the thermoplastic composition.

References Cited in the file of this patent UNITED STATES PATENTS Wiley et al. June 6, 1939 OTHER REFERENCES Beilsteins Handbuch Der Organischen Chemie Erstes (Copy in Sci.

Lib.) 

1. A COMPOSITION OF MATTER COMPRISING A CELLULOSE ESTER PLASTIC MOLDING COMPOSITION SELECTED FROM THE GROUP CONSISTING OF CELLULOSE ACETATE AND CELLULOSE ACETATE BUTYRATE AND A SMALL STABILIZING AMOUNT OF AN ALKOXYPHENYLGLYCIDE ETHER SELECTED FROM THE GROUP CONSISTING OF O AND P-ALKOXYPHENYLGLYCIDE ETHERS IN WHICH THE ALKYL RADICAL OF THE ALKOXY GROUP IS AN UNSUBSTITUTED ACYCLIC ALKYL RADICAL OF 1 TO 4 CARBON ATOMS INCLUSIVE. 